Agentes econômicos com posição dominante são capazes de se conduzir de maneira independente na sua atividade comercial. Da mesma forma, possuem todos os incentivos para manutenção desta posição, em detrimento de seus concorrentes, fornecedores e clientes. O presente trabalho visa, inicialmente, em estudo comparado da doutrina e jurisprudência no Brasil, União Europeia e Estados Unidos, identificar os elementos de cognição da teoria do abuso de posição dominante para cinco modalidades de conduta. A partir daí traçamos seus elementos de correlação com o propósito de sugerir uma teoria aplicada ao ordenamento jurídico pátrio, que passa pelo reconhecimento da concorrência como garantia institucional, de forma a estabelecer-se igualdade material segundo a teoria da função social dos meios de produção. A presença constante da concorrência nos mercados deve ser tratada como presunção de bem-estar social. E finalmente, valendo-se destes elementos de suporte, propomos uma teoria da responsabilidade especial para agentes econômicos em posição dominante, que implicaria o dever de autoaplicação dos limites permitidos para sua conduta comercial, cujo descumprimento ensejaria presunção relativa de efeitos deletérios ao mercado, segundo os parâmetros propostos. / Firms enjoying dominant position are able to conduct themselves independently in their commercial activities. Likewise, they hold all due incentives to maintain such position, in detriment of their competitors, suppliers and clients. The present work aims, initially, through a comparative study of the Brazilian, the European Union and the United States\' legal doctrine and jurisprudence, to identify cognitive elements of the abuse of dominance theory, for five different natures of conducts. Subsequently, we identify their elements of connection with the purpose of suggesting a theory applicable to the local legal system, which includes the recognition of competition as an institutional guarantee, so to establish a material equality according to the theory of social function of productive assets. The constant presence of competition on the markets shall be treated as a presumption of social welfare. And finally, based on such supportive elements, we propose a theory of special responsibility for dominant firms that implies in a duty of self-application of the permitted limits for their commercial conduct, and which infringement would entail a relative presumption of harmful effects to the market, pursuant to the proposed parameters.

Agentes econômicos com posição dominante são capazes de se conduzir de maneira independente na sua atividade comercial. Da mesma forma, possuem todos os incentivos para manutenção desta posição, em detrimento de seus concorrentes, fornecedores e clientes. O presente trabalho visa, inicialmente, em estudo comparado da doutrina e jurisprudência no Brasil, União Europeia e Estados Unidos, identificar os elementos de cognição da teoria do abuso de posição dominante para cinco modalidades de conduta. A partir daí traçamos seus elementos de correlação com o propósito de sugerir uma teoria aplicada ao ordenamento jurídico pátrio, que passa pelo reconhecimento da concorrência como garantia institucional, de forma a estabelecer-se igualdade material segundo a teoria da função social dos meios de produção. A presença constante da concorrência nos mercados deve ser tratada como presunção de bem-estar social. E finalmente, valendo-se destes elementos de suporte, propomos uma teoria da responsabilidade especial para agentes econômicos em posição dominante, que implicaria o dever de autoaplicação dos limites permitidos para sua conduta comercial, cujo descumprimento ensejaria presunção relativa de efeitos deletérios ao mercado, segundo os parâmetros propostos. / Firms enjoying dominant position are able to conduct themselves independently in their commercial activities. Likewise, they hold all due incentives to maintain such position, in detriment of their competitors, suppliers and clients. The present work aims, initially, through a comparative study of the Brazilian, the European Union and the United States\' legal doctrine and jurisprudence, to identify cognitive elements of the abuse of dominance theory, for five different natures of conducts. Subsequently, we identify their elements of connection with the purpose of suggesting a theory applicable to the local legal system, which includes the recognition of competition as an institutional guarantee, so to establish a material equality according to the theory of social function of productive assets. The constant presence of competition on the markets shall be treated as a presumption of social welfare. And finally, based on such supportive elements, we propose a theory of special responsibility for dominant firms that implies in a duty of self-application of the permitted limits for their commercial conduct, and which infringement would entail a relative presumption of harmful effects to the market, pursuant to the proposed parameters.

Title: Special responsibility of undertaking in dominant position Author: Iva Čechráková Department: Department of Business Law Supervisor: JUDr. Daniel Patěk, Ph.D Abstract: This thesis deals with the doctrine of special responsibility of the dominant undertaking and related issues. The special responsibility of the dominant undertaking is the obligation not to allow its conduct to impair genuine undistorted competition on the common market. The doctrine of the special responsibility is tied to the prohibition on abuse of such position. One concept could not be assessed without the other, because the concept of special responsibility of the dominant undertaking is a fundamental principle for the application of the prohibition on abuse of such position. Based on that it is necessary to describe in this thesis the prohibition on abuse of dominant position together with selected prohibited practices, in which the special responsibility of the dominant undertaking is reflected. This responsibility presupposes a higher standard of vigilance reflected in the conduct of such an undertaking, because an undertaking in dominant position on the relevant market could not take all actions that the other undertakings lacking such market power could do. The question of the superdominant undertakings and the scope of...